The degree of operating leverage is defined as:

Question $9$ options:

$1)$

$\%$ change in EBIT$/\%$ change in contribution margin

$2)$

$\%$ change in EBIT$/\%$ change in variable cost

$3)$

$\%$ change in sales$/\%$ change in EBIT

$4)$

$\%$ change in EBIT$/\%$ change in sales